This invention relates to an assembly of a seat frame for an automobile seat, slide rails arranged in the seat frame for enabling the adjustment of the seat location in the longitudinal direction of the automobile, and a locking device for locking the slide rails.
A conventional assembly as shown in FIGS. 1 and 2 in which a seat frame, slide rails and a locking device are illustrated in a perspective view. In FIG. 1, a reference numeral 01 shows a seat frame for mounting a cushion body thereon. Slide rails 02 are secured to the under-surface of the seat frame 01 by means of bolts 03 and nuts 04, for allowing the adjustment of the seat position in the longitudinal direction of the automobile. The slide rails 02 are usually composed of a lower rail 06 and an upper rail 05 which slidably engages with the lower rail 06, as shown in FIG. 2. The abovementioned seat frame 01 is secured to the upper rail 05 and moved in the longitudinal direction in accompany with the movement of the upper rail 05. The lower rail 06 is fixed to a chassis by a suitable bracket not shown.
In order to hold the seat at an appropriate position after the upper rail 02 has been moved, it is necessary to arrange a device for locking the upper rail in relation to the lower rail. Although there may be a number of types of such locking devices, a most fundamental one is shown in FIG. 2. In this conventional locking device, an engaging member 07 partly having a tooth portion is welded to the lower rail 06, and a stopper 08 having a tooth portion at its lower end is secured to a shaft of a lever 09 for allowing swinging movement in relation to the upper rail 05. The tooth portion of the stopper 08 can mesh with the tooth portion of the engaging member 07 for holding the seat in position. Thus, the movement of the seat in the longitudinal direction and the holding thereof can be governed by the engagement and disengagement between the tooth portion of the stopper 08 and that of the engaging member 07.
The seat frame 01 for mounting a seat thereon, and slide rails 02 are separately manufactured and assembled with each other by the bolts 03 and nuts 04 in the final manufacturing stage. Accordingly, the locking device is secured to the slide rails 02, and the assembling of the seat frame 01 and the slide rails 02 necessitates redundant parts and works. Moreover, the superposed arrangement of the seat frame 01 and the slide rails 02 produces increase of the total weight and cost, and also problems in quality.